A variety of portable doorway recreation apparatus are known in the art. Commonly these apparatus include generally L-shaped frames having a horizontal support attached to the riser of the L-shaped frame and a horizontal bar (often used as a pull up bar) attached to the base of the L-shaped frame. In use, the horizontal support is brought into contact with the top surface of trim at the top of one side of a doorway and the bar spans the other side of the doorway engaging the trim or wall beyond the vertical edges of the doorway. These apparatus are suitable for use under vertical loads on the horizontal bar such as pull ups where a vertical load on the horizontal bar causes a moment of force in conjunction with the horizontal support which effectively locks the apparatus in place as described above. However, horizontal loads which may be introduced, by way of example, by swinging, can cause the horizontal member to disengage from the top of the door trim, causing the apparatus to fall. Representative devices including this general configuration include Vanderbleek, U.S. Pat. No. 5,417,628 and Winblad, U.S. Pat. No. 3,915,452. Winblad tries to address this problem by providing an adjustable safety lock which includes an L-shaped member slidably mounted to a support spanning the doorway frame opposite the horizontal support. The L-shaped member can be pressed into contact with the underside of the top of the doorway frame and is intended to lock the apparatus in place on the doorway. While this safety lock provides some stability under horizontal loads, it is inadequate under significant or abrupt side to side swinging motion loads such as might be present with a swing or a punching bag mounting to the portable chinning bar assembly of Winblad, or from any athletic exercises involving full-body motion swinging.
The portable doorway recreation apparatus disclosed herein is intended to overcome one or more of the problems discussed above.